The Universe. Our Solar System. Uranus.

Uranus is the third biggest planet in the solar system and the only planet that rotates on its side. Scientists think it may have been knocked over onto its side by another planet long .
This means that some parts of Uranus can't be reached by the Sun for long periods of time. Some nights can last as long as 40 Earth years .
Uranus was the first planet to be discovered by a telescope by Sir William Hershel in 1781.
The core of the planet is made up of ice and rock making it the coldest planet in the solar system with temperatures of -224°C, 32 times colder than the average on Earth.
Even though you could see it without a telescope, it hadn't been noticed before that time because it is quite dim and has a slow orbit.